Smoggy Sequoias

by Loose Leaf Team

By Katrina Marland

Giant sequoias in Sequoia National Park. Credit: James Berk/Flickr

More often than not, you expect a park or forest to have pretty clean air. Even more so if it happens to be a well-known place, located far from the nearest urban center that could be smogging up its air. But sadly, this is not always the case. Sequoia National Park, home to some of the biggest and oldest trees in the U.S., is also home to a higher level of air pollution than any other national park.

There are 52 national parks in the U.S. that monitor their air quality each day to make sure that it is safe for visitors. High temperatures, levels of smog and levels of certain allergens or pollutants can all add up to make a bad air-quality day. Ozone in particular can be a nasty problem, capable of literally causing lungs to blister when it’s found at high enough concentrations. That national parks — the places we go to get away from cities and their many urban problems — also have to monitor for air pollution is a bit alarming. This week, the EPA and the National Park Service released a list of the 10 national parks with the worst pollution in 2011 based on ozone levels and days that failed to meet EPA standards for air quality, and Sequoia National Park topped the list.

Despite its reputation for immense trees and remote forests, Sequoia had a total of 87 days that failed to meet federal air-quality standards in 2011 — and it’s hardly a new problem. Park employees and volunteers have come to expect regular lectures on the dangers of air pollution and watch as once-clear vistas have become routinely wreathed in smog. In fact, according to the National Park Conservation Association (NPCA), Sequoia National Park has levels of ozone comparable to those in major cities like Los Angeles. Already this year, though summer has just begun, the park has seen levels of ozone well beyond those set by federal health standards.

How can this be the case when the park is miles away from the closest city? Unfortunately, it comes down to a quirk of geography. The park lies north of the San Joaquin Valley, which contains several major trucking highways, a number of power and food-processing plants and acres upon acres of farmland overseen by diesel-powered machinery. Pollution from this region is pushed north by winds off San Francisco Bay and meets the cooler air moving south, creating an eddy that traps the polluted air in the region, which gives it a chance to seep into the area where the park is located.

View from webcam of smog in Sequoia National Park. Credit: National Park Service

Human safety is certainly important, but such severe air pollution in what is supposed to be a remote, natural location also begs the question, what about the trees? Scientists are uncertain what effect long-term exposure to these levels of ozone might have on the environment in these locations, though foresters do see needles turn yellow as the trees soak up ozone, which interferes with their ability to photosynthesize. Young seedlings also struggle to survive and grow with such obstacles to overcome.

With this disturbing news about air pollution in national parks, we can only hope that Sequoia and other parks will benefit from legislation like the Clean Air Act, through which officials aim to give the region pure, clean air by the year 2064. The problem is that the only way to cut down on the pollution that enters Sequoia is to cut down on the pollution in the entire San Joaquin Valley air basin — a tall order given the sheer number of sources of pollution.

(500) Jobs of Summer

by Amanda Tai

Credit: a loves dc/Flickr

Memorial Day weekend is viewed as the official kickoff of summer. This past weekend, many folks headed to the beach or gathered at backyard barbeques to celebrate the holiday. It’s also the time of year when schools let out, and young people start looking for summer jobs. But unlike the flocks of interns that flood D.C. in the summer, some young people are planning to spend their summers working outside. Thanks to a new federal grant program, there are even more opportunities for youth to work outside this summer. With $3.7 million available for conservation projects, the grant will help employ more than 500 youths over the summer, adding to the existing 20,000-plus youth summer employment opportunities in national forests, parks and wildlife refuges.

Since President Obama launched his America’s Great Outdoors Initiative back in 2010, conservation and outdoor recreation have been highlighted as ways that we can protect our natural heritage. The U.S. Department of Agriculture (USDA), U.S. Department of Interior (DOI), U.S. Environmental Protection Agency (EPA) and the Council on Environmental Quality (CEQ) worked together to develop a conservation action plan after receiving more than 100,000 public comments.

A U.S. Fish and Wildlife Summer Intern. Credit:

In response to the Obama administration’s call to expand youth engagement in the outdoors, DOI Secretary Ken Salazar, USDA Secretary Tom Vilsack and CEQ Chair Nancy Sutley recently announced the creation of a new competitive grant program to expand the summer youth corps on public lands. The grant program is part of a new Youth Initiative funded through the Bureau of Land Management (part of DOI), the National Fish and Wildlife Foundation, the U.S. Forest Service and private partners from the America’s Great Outdoors development initiative. The initiative’s website serves as an educational resource for youth, provides an events calendar to find local opportunities to engage and even has an online job search available.

Secretary Salazar noted the importance of engaging young people in working on public lands and developing the next generation of land stewards: “President Obama’s call to expand summer job opportunities for young people is helping us engage and train the next generation of natural resource professionals and build a workforce that represents all of America.” So, whether it’s indoors or outdoors, an intern at an environmental nonprofit or working in a national forest, it’s encouraging to see how summer jobs are shaping the future of conservation.

Geology vs. Ecology

by Loose Leaf Team

By Michelle Werts

Thirty-two years ago this month, Washington’s Mount St. Helens erupted and collapsed, creating a massive avalanche and a stone- and ash-filled wind that would decimate the surrounding countryside. Nearly 150 square miles of forest were destroyed almost instantly — and then the eruption continued for nine hours. What was once a lush, green landscape was now a barren, gray landscape, but over time the green has slowly returned to Mount St. Helens, as evidenced in this recently released Landsat timelapse from NASA’s Goddard Space Flight Center.

Note: The red in the first few years is how Landsat used to register vegetation.

As shown in this photo taken after the eruption (use the sign as a comparison point between the two photos), Mount St. Helens’ eruption destroyed the old-growth forest.

Mount St. Helens’ eruption destroyed the old-growth forest (use the sign as a comparison point between the two photos). Credit: U.S. Forest Service

In 1979, before the eruption, the ridges north of the volcano were shrouded in old-growth Pacific silver fir and mountain hemlock forests.

In 1979, before the eruption, the area was covered in old-growth Pacific silver fir and mountain hemlock forests. Credit: M. Hemstrom/U.S. Forest Service

Through this video, you can see how vegetation has slowly returned to the Mount St. Helens area while the surrounding areas have been constantly evolving, as well. And for 30 years, scientists have been studying the area around the famous volcano to gather new insight into how areas recover from such catastrophic events. Here are some highlights of what they’ve learned:

  • Legacies can regrow a forest: At the time of the eruption, scientists believed that Mount St. Helens’ ecology would renew the barren landscape with help from species once unknown to the area. Some did, but much of the regrowth can also be attributed to “biological legacies” — the fallen trees, buried seeds and amphibians that survived the blast and have been resilient restarters of the green spaces around the volcano.
  • Thousands of acres of dead trees don’t necessarily equal fire and insect outbreaks: Many advocated for rapid salvage logging of the trees destroyed by the eruption, but in the 110,000-acre Mount St. Helens National Volcanic Monument created in 1982, no such logging was completed — and no massive fire or insect outbreaks occurred. It turns out that volcano ash reduces flammability and repels insects.
  • Native is better: Non-native seeds were spread around Mount St. Helens to help minimize erosion, but it wasn’t very successful. However, natural revegetation was successful in the area, showing that native seeds should always be considered first for erosion control efforts.

While 30 years might seem like a long time and many plants, trees and animals have repopulated this once-ravaged landscape, in ecological terms, recovery has only just begun. It’ll take centuries for the old-growth forest of firs (like Pacific silver and Douglas-fir) and hemlocks to regenerate fully. It’s amazing how one geologic event — a 5.1 Richter-scale earthquake that shook the volcanic mountain, causing the collapse and eruption — can destroy centuries of ecological work. And, it serves as a lesson that once destroyed, nature is not always easy to replace, but the Mount St. Helens area is making a mighty attempt.

Mount St. Helens in 2007

Mount St. Helens in 2007. Credit: Adrien Vieira de Mello (adrivdm)/Flickr

At Crater Lake

by Loose Leaf Team

By Katrina Marland

When I was seven, my family took the first of many summer vacations traveling through the Pacific Northwest. We camped, hiked, fished and traveled to all kinds of places — from caves to redwood forests to rocky beaches. Some sites we saw only once, others we liked so much that we returned each year. Though I loved every one of these trips, no single experience had quite the impact as the first time I saw Oregon’s Crater Lake. My family reached the viewing point along the rim; I looked out at the immense scene before me and was completely, breathlessly awestruck with the size of it all. Knowing little about natural history at the time, all I knew was that at some point, somehow, nature made all this.

Crater Lake

Crater Lake Credit: Frank Kovalchek

Earlier this week, Crater Lake National Park (CLNP) celebrated its 110th anniversary. Established May 22, 1903, the park covers more than 183,000 acres around Crater Lake itself. At less than six miles across, the lake certainly isn’t the largest in the U.S., but with a depth of 1,943 feet, it is easily the deepest. In fact, it is one of the 10 deepest lakes on the entire planet. The blue water that the lake was once named for — so clear because the lake is fed almost solely from snowfall — sits inside a massive crater that formed roughly 7,700 years ago when the stratovolcano Mount Mazama erupted and collapsed. The resulting crater is so deep that the lake itself only begins more than 2,000 feet below the crater rim. So when you look down into the lake, you look way, way down — so far that it seems impossible.

A tree on the rim of Crater Lake Credit: Frank Kovalchek

The rim itself sits at about 7,000 feet above sea level, so if you manage to turn your back on the sight of this lake that seems to sit on the top of the world, you still have a fantastic view of the rest of the Cascades sprawled out around you — much of it more pristine than you could hope to see. Because the park was established, and therefore protected, before commercial logging reached the area, almost all the forests on CLNP are old growth. At the high altitude and with the inhospitable soil that comes from taking root in an area with so much volcanic activity, many of the trees that you can see from Crater Lake have fought to be there for longer than most of us have been alive. So while you may visit to see the lake itself — and I strongly suggest you do — don’t forget that it sits amidst a landscape carved out by raw, natural energy and covered with some of the most determined life on the planet.






Trees Can’t Swim

by Loose Leaf Team

By Michelle Werts

Martha’s Vineyard. It’s a place I’ve always associated with vacation cottages and well-to-do New Englanders. Little did I know that this set of islands off of Cape Cod, Massachusetts, is actually a hotbed for forest researchers, who are studying some interesting phenomena on this idyllic locale.

The breach of North Point Beach on April 20, 2007

The breach of North Point Beach on April 20, 2007. Credit: Bill Brine/Flickr

First, there’s the case of the forest consumed by the sea. Since an April 2007 storm breached Norton Point Beach — the storm cut this barrier beach in half — the ocean has been eating away the beach and land at Wasque Point, aka the southeast corner of Chappaquiddick Island. With the beach now gone, the waves are attacking the bluffs — and the pitch pine forest that grows there. As the bluffs go, so do the pitch pines, tumbling into the ocean currents below. And as Harvard Forest Director David Foster told the Harvard Gazette, pitch pine forests are “very salt tolerant, but they’re not that salt tolerant.”

Foster, a paleoecologist who studies how landscapes change over long periods of time, plans on bringing research fellows and students to Wasque this summer to study how this environment is rapidly changing thanks to one destructive storm and the power of the ocean. As The Trustees of Reservations Director Chris Kennedy, whose conservation group manages the area around Wasque Point, told the Vineyard Gazette, “There’s nothing to block the waves. … They’re crashing right against the cliffs, which are just sand. So we can lose 10 to 15 to 20 feet overnight.” At other points in the area, the surf is adding feet of sand to the beaches and is creating a myriad of sandbars offshore. Kennedy expects that in two to five years that part of Norton Point Beach that is migrating west parallel to the shore will reconnect to the island and hopefully reduce the extreme erosion.

A stretch of Chappaquiddick Island that is being eroded

A stretch of Chappaquiddick Island that is being eroded (pictured in July 2011). Credit: Alexander Cheek (arwcheek)/Flickr

This isn’t the only drastic change to Martha Vineyard’s landscape in the 21st century. In 2007, the island’s Polly Hill Arboretum experienced a massive oak die-off, and according to Foster, this wasn’t the first time that the Vineyard’s oaks died en masse — it had happened 5,000 years earlier. Foster and other researchers had previously studied a massive oak die-off on the island and determined that 5,000 years ago, the oaks succumbed to a warming period in Earth’s history and were replaced by beech trees that flourished for 1,000 years before the oaks were able to reassert themselves. The 2007 die-off, according to Foster, appears to be following that pattern, as insects — which were likely more prevalent due to a warming climate — attacked the trees for three consecutive years before the oaks lost the battle. Now, five years later, history continues to repeat itself as where once oak trees stood, young beech trees are rising in their place.

So, Norton Point Beach will attach itself to Wasque and thus slow the erosion that is decimating the coast, and Martha Vineyard’s birch trees, bushes and shrubs are sprouting up to take the place of the forests that were lost. We get two prime examples of how nature is always changing and always evolving — they just both happen to be on the same tiny set of islands. Astonishing.

Trees Make Urban Communities More Livable

by Amanda Tai

I’ve already talked about the importance of trees in urban areas and the many benefits they provide — like increased opportunities for outdoor recreation, community economic growth and improved air quality. Now, the buzz around urban forests has reached the ears of Congress with the Urban Revitalization and Livable Communities Act, H.R. 709. The bill’s language requires the Department of Housing and Urban Development to establish and administer a grant-giving program for park and recreational projects in urban areas. Many types of projects could be funded by this program, like planting trees in an abandoned lot to turn it into a community green space or engaging inner-city youth in outdoor recreation. The bill would appropriate $445 million per year to the program through fiscal year 2021. This funding would not only create an immediate impact, but would also establish an investment in the future of urban communities and recreation. To be eligible for a grant, applicants would have to submit a five-year plan indicating their commitment to maintain and monitor their project.

Forest Park in Portland, OR. Credit: sha-put-ski/Flickr

This isn’t the first time there has been a bill supporting urban restoration work. In 1978, the Urban Park and Recreation Recovery (UPARR) Act established a program that provided matching grants for restoring distressed urban areas. UPARR hasn’t been funded since 2002, but the facilities and sites it funded are still in use today and remain protected under the act’s provisions.

While urban parks and recreation may exist on Congress’ radar, it’s still only a faint blip. The Urban Revitalization and Livable Communities Act has sat around with no movement for the past two and a half years. First introduced in 2009 by Representative Albio Sires (D-NJ), the bill was referred to committee, but never moved on to a full House vote. In February 2011, Sires reintroduced his bill in a second attempt to build congressional support. Groups like the Urban Parks Coalition and the Sustainable Urban Forests Coalition — of which American Forests is a member — are advocating for the passage of this bill, which has currently been sent to House subcommittees to await further action.

We all know it’s tough to get any movement in Congress these days, but urban forest advocates continue working so that they’ll be ready when the ball starts to roll again. Keeping the discussion alive will show Congress that funding for urban parks and forests is a priority issue. After all, many members of Congress live in the D.C. metropolitan area. I imagine they’ve seen and enjoyed the trees and parks near their houses. That brings the issue is a lot closer to home than Congress may realize.

Law in the Amazon

by Alison Share, Environmental Public Policy Associate, Crowell & Moring LLP
Amazon rainforest, near Manaus, Brazil

Amazon rainforest, near Manaus, Brazil. Credit: Neil Palmer/CIAT

Welcome back to the world of environmental law and policy! Most of these posts will address domestic concerns, but today, we begin with one of the largest forests in the world — the Amazon rainforest. In the vein of Harper’s Index, one of my most favorite monthly reads, I bring you a few interesting statistics:

  • Number of acres of forests and grasslands managed by the U.S. Forest Service: 193 million
  • Number of acres of rainforest in the Amazon Basin: approximately 1.4 billion
  • Percentage of the rainforest that is solely within Brazil: 60 percent, or approximately 840 million acres
  • Number of law enforcement personnel employed by the U.S. Forest Service: 737
  • Average number of acres of forest and grassland per agent: 261,872
  • Number of federal environmental enforcement agents in Brazil: 1,300
  • Average number of acres of Brazilian rainforest per agent: 646,153

The U.S. Forest Service also has a stewardship role, in conjunction with state and local authorities, over millions of acres of urban forests. The Forest Service has firefighters and numerous other types of employees; however, the fact remains: In Brazil, enforcement agents have much more territory to cover than their counterparts in the United States. That territory is not grassland or forests with roads and paths and trails. The Amazon rainforest contains one in 10 known species of plants and animals in the world. It is dense and, in large part, unmapped. Both farmers and ranchers own land within the rainforest, and Brazil has passed laws and regulations governing how that private land is cultivated. One of those regulations requires farmers to preserve or replant trees on 80 percent of their land that is located within the Amazon rainforest. Trees and woodlands that border rivers and stand on hilltops and steep inclines are not included in the total amount of required preserved forestland.

Farmland near Manaus, Brazil

A boy walks through his family’s farmland near Manaus, Brazil. Credit: Julio Pantoja/World Bank

On April 25 of this year, the Brazilian Congress passed a new bill that pitted the agricultural lobby against environmental groups, coupled with a large dose of governmental jostling. This bill, which underwent a significant alteration by lawmakers to include more lenient language on behalf of the agriculture lobby, allows previously exempt woodlands to be counted in the total amount of acreage required by law to be preserved. Farmers who had deforested land in order to create arable land for agriculture can now replant less acreage, but still comply with the overall requirement of 80 percent preservation. The new bill also allows farmers to cultivate farmland up to rivers’ edges, should they choose to do so. Previous buffer zones of 30 to 100 yards of forest required between the river and worked land were stripped away by the new bill. Finally, the bill grants an amnesty for fines levied against farms and ranches that had previously cleared more than the legally allowed amount of acreage.

Environmentalists decry the new bill as too lenient in terms of preservation and restoration and call the amnesty a free pass for environmental crimes. The main fear of the bill is that it will result in the replanting of fewer deforested acres than under the old regulations.

In June, the United Nations Conference on Sustainable Development (the Rio+20 Summit) descends upon Brazil to discuss global environmental policy. This new forest bill, watched closely by other developing nations, will surely be a topic of conversation among the attendees, especially considering the summit’s themes of poverty eradication through sustainable development and the creation of an institutional framework for that development. Brazil faces innumerable challenges when it comes to its rainforest. And the trials that the nation must undertake in balancing the various interested factions can serve as an education for us all.

From Sea To Tree

by Loose Leaf Team

By Katrina Marland

Manta ray

Giant manta ray Credit: Vlad Karpinsky

You’ve heard me talk a lot about how everything is connected. It’s a theme in the natural world that I find completely fascinating, so you can imagine how much I enjoyed this recent article from Yale Environment 360 about finding a connection between trees and giant manta rays. Yes, I said giant manta rays. These creatures can grow to more than 25 feet across, but even small changes in the ocean food web can significantly impact their populations. So, I bet you’re thinking, “If these creatures are so tied to the deep blue sea, what could they possibly have to do with decidedly land-bound trees?”

U.C. Berkeley marine biologist Douglas McCauley found himself asking a similar question. He and his colleagues were tracking Pacific manta rays around the Palmyra Atoll, a ring of islands halfway between Hawaii and American Samoa that are mostly uninhabited and undeveloped. The majority of the atoll is covered in thick native forests, broken in some places for sections of coconut palms, which are not native to the islands, but were brought there by humans. As McCauley and his team traveled the waters around the atoll, monitoring their mantas, they noticed an odd pattern: No matter which rays they followed, sooner or later, they ended up in water near Palmyra’s native forests. But never near the coconut palms.

To find out why the rays seemed to so strongly prefer the native-forested coastlines, the team tested the waters near both types of vegetation and found a lot more fish in those around the native forests than the palms. It seemed that the marine life really did prefer the waters around the areas of native forest — an ecosystem they couldn’t even touch. The scientists discovered that the reason behind this starts not with a manta ray or even a tree, but with a bird.

Birds on Palmyra Atoll

Birds nest in native trees on Palmyra Atoll Credit: Island Conservation

Many bird species take advantage of the undisturbed habitat on Palmyra Atoll, and migratory species use it as a rest stop in the middle of the Pacific Ocean. For seabirds like the red-footed booby and white tern, there is no lack of fishing in the surrounding waters. These birds have their choice of habitat on the island: coconut palms or the native forest. The majority opt for the native forest because while palm fronds may be pretty, the branches of native trees form a more stable canopy for the birds’ rest and protection. Where more birds rest, there are, understandably, more bird droppings, which contain a lot of nitrogen — a natural fertilizer. During their tests, McCauley’s team found that the soil in the native forests had a nitrogen level five times higher than the palm forests. The trees and plants absorb the nitrogen, which falls back to the ground in the form of leaves and twigs, creating a nice, nitrogen-rich layer on the forest floor. When it rains — and Palmyra gets about 175 inches of rain each year — the nutrients from the soil get washed out into the ocean, feeding all the organisms that live there, including plankton. McCauley’s team found that there were three times as many zooplankton off the coast of the native forests than off the palm-forested coastlines. And what eats plankton? Manta rays.

It all comes full circle. Birds catch and eat fish from the ocean, then rest in the native forests on land. Their droppings fertilize the soil, helping the trees grow and concentrating the nitrogen in the soil, which washes out to sea and feeds everything there, ending up right back in the fish that will be caught by another bird.

While we often realize the connections between flora and fauna in the same ecosystem, or even between land-based ecosystems, it is easy to forget how easily an action onshore can influence something deep in the sea — and vice versa. McCauley’s study is a fantastic example of a connection we rarely make: That marine and terrestrial ecosystems, though sometimes miles apart, are anything but independent.


Endangered Flora and Fauna

by Loose Leaf Team

By Michelle Werts

Today is Endangered Species Day. Originally, I was going to honor this special day by posting pictures of cute, cuddly, nifty and sadly endangered species — don’t worry, that’s still happening — but alas, environmental news that affects some of our endangered friends has crept into the headlines this week, so I feel like maybe we should talk about that first.

Smithsonian National Zoo Gorillas

Credit: Smithosonian’s National Zoo/Flickr

A new study released by the University of Washington – Seattle reveals that in within 100 years, about 90 percent of mammals will have lost their native habitat range due to climate change. Of these mammals, 10 percent of them won’t be able to move fast enough to keep up with their shifting habitat. According to the study, the most at-risk species are actually primates because of the changing climate and because they won’t be able to get to live-able conditions fast enough. Also of concern are animals in tropical regions, which are more susceptible and sensitive to climate changes. The mammals that are expected to fare better are those that can move greater distances, such as elk, moose and sloths. Scientists hope that this new research will enable them to focus on creating migration corridors for those animals most in need.

Also released this week was the Center for Biological Diversity’s report stating that 90 percent of species that are listed under the Endangered Species Act are recovering at their predicted rate. Yay! According to the report, species on the list are recovering, on average, within 25 years of placement on the list. The downside to this news is the fact that there are more species that should be listed as endangered or threatened than there are funds to protect them. For instance, last summer, the U.S. Fish and Wildlife Service (FWS) declared that listing the whitebark pine was warranted, but precluded — meaning that the species should be on the endangered list, but can’t be because of lack of funding. This is why American Forests supports more funding for the FWS budget for endangered species during the appropriations process.

And just what kind of animals and plants is the Endangered Species Act protecting and revitalizing? Let’s take a look.

Polar bears have been listed as threatened since 2008

Polar bears have been listed as threatened since 2008. Credit: USGS

Florida scrub-jay

Florida scrub-jay has been listed as threatened since 1987. Credit: Matthew Paulson (Photomatt28)/Flickr

Green pitcher-plant

Green pitcher-plant has been listed as endangered since 1979. Credit: James Henderson/Golden Delight Honey/

Florida torreya, aka Florida nutmeg

Florida torreya, aka Florida nutmeg, has been listed as endangered since 1984.

Wyoming toad

At its full size, the Wyoming toad is only two inches long and has been listed as endangered since 1984. Credit: Mike D. (wuperruper)/Flickr

Karner blue butterfly

Karner blue butterfly has been listed as endangered since 1992. Credit: Catherine Herms/The Ohio State University/

A History of Fire

by Loose Leaf Team

By Katrina Marland

Thanks to a particularly dry April, Arizona is kicking off the 2012 fire season with several intense fires. In the Mazatzal Wilderness, which spans Tonto and Coconino National Forests, more than 4,600 acres are currently ablaze, and an impressive cadre of 200 firefighters and 11 aircraft are working to contain it. Other fires bring the state’s total to four major blazes, with roughly 12,000 acres aflame and some evacuations already taking place — something that doesn’t usually happen until later in the season, when the major fires are expected. And Arizona isn’t the only one; Colorado is on fire as well. At about 640 acres, the fire is significantly smaller than Arizona’s but is causing a good deal of anxiety as it bears down on the town of Fort Collins, home to a population of more than 140,000.

Forest Fire Credit: USDA Forest Service

To most of us, news of wildfires across the southwest U.S. is upsetting, but hardly unexpected. After all, we’ve been hearing similar news every summer for decades. Even the oldest person probably can’t remember a time when major wildfires in that region were very unusual. But a recent study on the topic shows that what we consider routine is actually a reflection of modern times — and not in a good way.

A team of researchers from Southern Methodist University (SMU) has used data from decades of tree-ring analyses to delve into the region’s ancient fire and climate history. Tree rings keep a record of major events like fires or volcanic eruptions, as well as climatic patterns, so studying them can tell scientists a great deal about times long gone by (check out the American Forests magazine article for more on tree rings). This particular study was the first of its kind, as it combined fire-scar records with tree-ring data from Ponderosa pines across the Southwest and used a statistical model to predict the fire history back as far as 1,500 years ago.

The team found that throughout history, as the climate changed, the weather patterns that bring about fires — dry, hot, often windy weather — remained consistent, arriving at the same intervals and staying for the same amount of time, which meant a fire season of average intensity and duration. Today, however, weather patterns change more frequently, with more frequent droughts and heat waves than in the past. In fact, according to the National Atmospheric and Oceanic Administration, we could be experiencing the warmest year on record, with March 2012 the warmest ever recorded and April following close behind with its third-warmest average national temp. The SMU study suggests that the “megafires” we regard as commonplace throughout the Southwest are anything but. Instead, they’re likely a result of unusually warm, dry conditions that we are experiencing because of climate change and human activity, especially fire suppression. Instead of the more frequent but less intense fires that burn away understory but leave healthy trees standing, we have today’s frightening infernos, which cause a lot more damage.